My high school boyfriend once asked if he could tell his friends we'd had sex. We hadn't yet, but after six months or so his crew was getting antsy. I imagined them in dank basements in between sips of Colt 45 beer asking, "Dude, what's taking so long? Don't you know what a girlfriend's for?"

So I did what any insecure 15-year-old would: I said "yes." If it made them shut up, I was for it. I didn't think about feeding a culture that degrades women and can lead to violence against them.

Now that culture has been thrust into the spotlight due to some unfortunate Facebook messages exchanged among University of Ottawa students. The five guys, four of whom were involved in student politics, were caught writing about student union leader Anne-Marie Roy in a sexually violent way.

The exchange included such gems as "someone punish her with their shaft" and "Well, Christ, if you f*** Anne Marie I will definitely buy you a beer." They have since sent her a letter of apology.

The content of their conversation is appalling, but most appalling is how common this type of dialogue is among groups of males. An extremely polite, 29-year-old friend of mine said "I was having conversations like that when I was 16 and at the same time I wanted to fall in love and give a girl flowers." He just couldn't talk about the second part, cause, you know, in the twisted world of male pressure being romantic with a woman is "gay."

Instead of being able to speak truthfully among one another, men feel pressure to brag about the number of girls they've slept with, how many tequila shots they fed those girls and how they degraded them during sex. Boys will be boys, right?

And maybe it starts off as hot air to impress the lads, but if men talk enough about how cool it is to demean women sexually, some of that talk is bound to turn into action. Indeed on Monday, the University of Ottawa's hockey team was suspended after an alleged sexual assault.

The team mentality is a key perpetrator of violence against women. If we're ever to stop rape culture, we must teach boys to grow into men who stand up to to dangerous group dynamics. Today, I wish I'd told my high school boyfriend to do just that.

Of course misogyny is deeply embedded in society -- it doesn't just magically appear when more than two guys enter a room together. But a gaggle of dudes exacerbates the problem. Blame the tenets of any social psych 101 class: "groupthink" and the "bystander effect." The former refers to the dangerous choices people make to fit in and the latter to how people are less likely to help a victim when others are around. Both play a big role in validating sexual assault.

Groupthink helps to explain the recent video of Saint Mary's University students (both men and women) chanting about the virtues of underage, non-consensual sex during frosh week. The same chant was repeated days later at the University of British Columbia. But even more sinister is how groupthink paired with the bystander effect leads to actual violence.

There are too many recent examples. Teenagers Rehtaeh Parsons and Audrie Pott both committed suicide after they reported being sexually assaulted at house parties by a group of boys (in Pott's case, her perpetrators were convicted). In Steubenville, two high school football players were found guilty of raping a 16-year-old girl while their friends took photos.

In all cases a group of guys got drunk and followed a herd mentality. Nobody wanted to break from the pack to question their despicable actions. They reassured each other the assaults were funny instead of criminal. Those watching took pictures instead of calling for help. On their own, it is unlikely the boys would have acted so horribly.

The group mentality of these wasted teens differs from that of psychopaths like Paul Bernardo and Karla Homolka, whose brutal assaults were soberly planned and executed without remorse.

That's not to say we should excuse teenage boys for ruining lives, but we should note the difference in motives. The Steubenville teens wept during their sentencing. In the courtroom, the convicted Ma'lik Richmond spoke directly to the victim's family. "I had no intentions to do anything like that," he said shakily. "I'm sorry to put you guys through this." He then broke down into tears.

We can't have a discussion about rape culture without acknowledging booze, which figured prominently in all of the above cases. But the group factor is just as strong. The U of O students weren't talking to each other while drunk at a party -- they were sitting on their computers just after 3 p.m. in the afternoon. They were fuelling each other's sinister thoughts rather than thinking as individuals.

Pat Marquis was a member of the Student Federation involved in the Facebook thread (he's since resigned). After the fact, he told The Canadian Press: "I didn't say much in that conversation, but I didn't stop it either ... There's a lot of boys' talk and locker-room talk that can seem pretty normal at the time, but then when you actually look back at it, it can be offensive."

There's been a lot of talk on university campuses about changing a culture that encourages the Blurred Lines mentality to sex. After the rape chant, Saint Mary's released a report with 20 recommendations. Among other things it called for the creation of a sexual response team and a plan to hold perpetrators more responsible. And while all these initiatives are helpful, the work needs to begin earlier. By the time they get to high school, teenage boys should be thinking about how to speak up in a group that makes them uncomfortable.

Sex-ed classes should offer advice about how to deal with dangerous peer pressure. Parents should talk to their sons about the social issues surrounding sex, along with the birds and the bees. And perhaps most importantly, older male figures like coaches, teachers and brothers should teach younger boys that degrading women isn't "cool."

Rehtaeh Parsons' father, Glen Canning, summed this up perfectly in a Huffington Post blog post: "Imagine the difference it would make if a man who jokes about rape and always doubts victims entered a room to silence, whispers, stares, and looks of disgust from other men. That is what we need to do as men." If one man stands up to a group, it will give others permission to do the same. Men who resist the herd mentality could be the most powerful weapon to fight sexual violence against women.